The alimentary canal is classic Mary Roach terrain: The questions explored in Gulp are as taboo, in their way, as the cadavers in Stiff and every bit as surreal as the universe of zero gravity explored in Packing for Mars. Why is crunchy food so appealing? Why is it so hard to find words for flavors and smells? Why doesn’t the stomach digest itself? How much can you eat before your stomach bursts? Can constipation kill you? Did it kill Elvis?

In Gulp we meet scientists who tackle the questions no one else thinks of – or has the courage to ask. We go on location to a pet-food taste-test lab, a fecal transplant, and into a live stomach to observe the fate of a meal. With Roach as our guide, we travel the world, meeting murderers and mad scientists, Eskimos and exorcists (who have occasionally administered holy water rectally), rabbis and terrorists – who, it turns out, for practical reasons do not conceal bombs in their digestive tracts. Like all of Roach’s books, Gulp is as much about human beings as it is about human bodies.

Gulp is a somewhat irreverent look at wonderful world of science related to food and digestion. In it, Roach looks at a lot of different experiments, research, jobs, and questions that we may or may not think of on our own. Some of them are quite mundane, but some – like the rectal holy water – are really quite out there. And in this book, Roach approaches these topics with the same kind of wry humour that I’ve always enjoyed in her work.

Having said that, I have to admit that I didn’t find this book quite as appealing as Stiff or Bonk. I thought that, since the subject of food interests me, I might find Gulp to be more interesting … but alas, that was not the case. I don’t think it’s because Roach did any less of a great job with Gulp than with her previous books. Rather, I think that the science of digestion is merely not as interesting to me. And that’s not to say that Gulp wasn’t interesting – it was – but simply that it didn’t compare on the same level.

Definitely give Gulp a go if you’re interested in digestion and current science. It won’t be a disappointment.